TWI830873B - Inorganic oxide particles, inorganic oxide particle dispersion, method for producing the same, and method for producing surface modifier - Google Patents

Abstract

The present invention provides an inorganic oxide dispersion (sol) in which inorganic oxide particles are dispersed in silicone oil. The present invention is a dispersion in which inorganic oxide particles surface-modified by a surface modification agent represented by the following general formula (1) are dispersed in silicone oil, [In formula (1), R ¹ represents a methyl group or an ethyl group, R ² represents an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 40 carbon atoms, or a combination thereof, and R ³ includes The linking group of chemical groups obtained by the reaction of B group and C group. B group is epoxy group, vinyl group, hydroxyl group or isocyanate group. C group is carboxyl group, acid anhydride group, amine group, thiol group, hydroxyl group or isocyanate group. , R ⁴ is an alkyl group with 1 to 10 carbon atoms or an aryl group with 6 to 40 carbon atoms, which may contain an epoxy group, vinyl group, hydroxyl group, isocyanate group, carboxyl group, acid anhydride group, amino group or thiol group. Or OH group or hydrogen atom, and the silanol group on the surface of the silica particle is modified by the OH group obtained by the hydrolysis of the OR ¹ group. The unit structure A includes the unit structure of the following general formula (1-1) and the following The unit structure of general formula (1-2), and the number of unit structures of general formula (1-1) contained in unit structure A and the number of unit structures of general formula (1-2) are n4 and n5 respectively, (In formula (1-2), R ⁵ represents an alkyl group or carbon atom with 1 to 10 carbon atoms that may contain an epoxy group, vinyl group, hydroxyl group, isocyanate group, carboxyl group, acid anhydride group, amino group or thiol group. aryl group (number 6 to 40, or OH group), n1 is an integer from 1 to 3, n2 is an integer from 0 to 1, n1+n2=3, n3=n4+n5, n3 is an integer from 1 to 100, 0 ≦n4≦100, 1≦n5≦100].

Description

Inorganic oxide particles, inorganic oxide particle dispersion liquid and manufacturing method thereof, and surface modification agent manufacturing method

The present invention relates to inorganic oxide particles surface-modified with a specific surface modifying agent. Furthermore, the present invention relates to a dispersion in which inorganic oxide particles surface-modified with a specific surface modification agent are dispersed in silicone oil and a manufacturing method thereof. Furthermore, the present invention relates to a method for producing a surface modification agent for surface modification of inorganic oxide particles.

Inorganic oxide particles, especially oxidized silicon particles, can be preferably used as a binder dispersed in silicone oil. For example, a dispersion (sol) of inorganic oxides such as silicon oxide, zirconium oxide, and titanium oxide dispersed in silicone oil can change the refractive index or mechanical properties by mixing it with a resin or coating it on a substrate. , so it is an effective material for improving refractive index or mechanical strength.

For example, Patent Document 1 discloses a coating liquid for forming a low-dielectric silicon oxide film containing a polyether-modified silicone oil, an alkoxysilane or a hydrolyzate of a halogenated silane, and it is described that it can form and be coated An insulating film with excellent surface adhesion, mechanical strength, chemical resistance, and excellent crack resistance (refer to patent application scope and abstract). Patent Document 2 discloses a coating composition for forming a lubricating releasable surface layer, which contains (A) a base composed of 70 to 90 mass % of hydrocarbon oil and 5 to 15 mass % of silicone oil, and (B) a base composed of A surface layer-forming component composed of 2.0 to 8.0 mass % of polysiloxane containing vinyl and 2.0 to 8.0 mass % of alkyltrialkoxysilane, and (C) silicon oxide fine powder, and it is stated that it can form an adhesion to a metal matrix A lubricating release surface layer with high adhesion to the active surface, excellent heat resistance, pressure resistance and durability (refer to patent application scope and abstract). Patent Documents 3 and 4 disclose that the surface of inorganic oxide particles such as silicon oxide particles is pre-bonded with a specific dispersant such as carboxylic acid or amine to have dispersibility in a hydrophobic solvent, and then the inorganic oxide particles are dispersed in the hydrophobic solvent. material particles, in a hydrophobic solvent, by pre-bonding the surface of the inorganic oxide particles with a specific dispersant and a surface modification agent made of a polydimethylsiloxane skeleton polymer with a single functional group at one end. Replacement, and after bonding the functional group of the surface modifier made of a polydimethylsiloxane skeleton polymer with a functional group at one end to the surface of the inorganic oxide particles, the resulting The surface-modified inorganic oxide particles of a polydimethylsiloxane skeleton polymer with a single functional group at one end are compounded with a silicone resin. It is also recorded that the silicone resin and inorganic oxide particles can be well compounded. Produce a composite composition that does not undergo phase separation or does not produce holes or cracks (refer to abstract, specification paragraphs [0039], [0042]). [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 11-50007 [Patent Document 2] Japanese Patent Application Publication No. 2012-115841 [Patent Document 3] Japanese Patent Application Publication No. 2012-021117 [Patent Document 4] Japanese Patent Application Publication No. 2013-064163

[Problem to be solved by the invention]

Patent Document 1 describes the use of polysiloxane having a reactive functional group (organic functional group) at the terminal, and the dehydration reaction between the functional group and the silanol group on the surface of the oxidized silicon particle forms a polysiloxane on the surface of the oxidized silicon particle. Technology for grafting polysiloxane, however, due to the different hydrophilicity and hydrophobicity of organic functional groups and silanol groups, it is difficult to fully react and graft polysiloxane on the surface of oxidized silicon particles. The technologies described in Patent Documents 3 and 4 also have the same problem. In Patent Documents 3 and 4, as mentioned above, it is described that after preliminarily bonding a dispersant such as carboxylic acid or amine to the surface of the silicon oxide particles, the silicon oxide particles are dispersed in a hydrophobic solvent, and then the surface of the silicon oxide particles is bonded in advance. The specific dispersant is replaced with a surface modifier made of a polydimethylsiloxane skeleton polymer with a single functional group at one end, and the polydimethylsiloxane skeleton polymer with a single functional group at a single end is bonded to the surface of the silica particles. This is a technology for obtaining surface-modified silicon oxide particles by using this functional group of a surface modification agent made of a siloxane skeleton polymer. However, like Patent Document 1, due to the hydrophilicity and hydrophobicity of the organic functional group and the silanol group Due to their different properties, it is difficult to fully react and graft polysiloxane onto the surface of oxidized silicon particles. Patent Document 2, as mentioned above, discloses a coating composition for forming a lubricating and releasable surface layer, which contains a base composed of a hydrocarbon oil and a silicone oil, and is composed of a vinyl-containing polysiloxane and an alkane. The surface layer-forming component composed of trialkoxysilane and silicon oxide fine powder are not described or taught, but the reaction of the vinyl-containing polysiloxane and alkyltrialkoxysilane with the silicon oxide fine powder is neither described nor taught. , and dispersed in silicone oil.

In the method of dispersing the oxidized silicon particles in silicone oil of a non-polar solvent by grafting polysiloxane on the surface of the oxidized silicon particles with a hydrophilic substance, if the above-mentioned prior art is used, the reactive functional groups (organic functional groups) The reaction between the silanol group on the surface of the oxidized silicon particles and the silanol group on the surface of the oxidized silicon particles is a reaction between organic substances and inorganic substances, so the reaction is not fully carried out, and there is a problem of difficulty in grafting polysiloxane on the surface of the oxidized silicon particles, and there are The problem is that it is difficult to obtain oxidized silicon particles with polysiloxane fully grafted on the surface of the oxidized silicon particles.

The present invention was completed in order to solve the above-mentioned problems and other problems, and its object is, for example, to provide a method for dispersing inorganic oxide particles having hydrophilicity on the surface through silanol groups or the like in silicon oxygen with good compatibility. Method for producing a surface modifier (surface coating agent) in a non-polar solvent (hydrophobic solvent) such as oil, inorganic oxide particles coated with the surface modifier, and surface-modified inorganic oxide particles dispersed in silicone Inorganic oxide dispersion (sol) in non-polar solvent such as oil and its production method. [Means used to solve problems]

As a result of actively examining the above-mentioned problems, the inventors found that the problems of the present invention can be solved by the following means, and thus completed the present invention. That is, aspects of the present invention are as follows. <1> An inorganic oxide particle whose surface is modified by a surface modifying agent represented by the following general formula (a), [In formula (a), S represents hydrolyzable silane, and K represents silica]. <2> An inorganic oxide particle whose surface is modified by a surface modifying agent represented by the following general formula (1), [In formula (1), R ¹ represents a methyl group or an ethyl group, R ² represents an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 40 carbon atoms, or a combination thereof, and R ³ includes The linking group of chemical groups obtained by the reaction of B group and C group. B group is epoxy group, vinyl group, hydroxyl group or isocyanate group. C group is carboxyl group, acid anhydride group, amine group, thiol group, hydroxyl group or isocyanate group. , R ⁴ is an alkyl group with 1 to 10 carbon atoms or an aryl group with 6 to 40 carbon atoms, which may contain an epoxy group, vinyl group, hydroxyl group, isocyanate group, carboxyl group, acid anhydride group, amino group or thiol group. Or OH group, and the silanol group on the surface of the silica particle is modified by the OH group obtained by the hydrolysis of the OR ¹ group. The unit structure A includes the unit structure of the following general formula (1-1) and the following general formula ( 1-2), and the number of unit structures of general formula (1-1) and the number of unit structures of general formula (1-2) included in unit structure A are n4 and n5 respectively, (In formula (1-2), R ⁵ represents an alkyl group or carbon atom with 1 to 10 carbon atoms that may contain an epoxy group, vinyl group, hydroxyl group, isocyanate group, carboxyl group, acid anhydride group, amino group or thiol group. Aryl group with number 6~40, or OH group or hydrogen atom), n1 is an integer between 1~3, n2 is an integer between 0~1, n1+n2=3, n3=n4+n5, n3 is an integer between 1~100 Integer, 0≦n4≦100, 1≦n5≦100]. <3> The inorganic oxide particles of <1> or <2>, wherein the average primary particle size of the inorganic oxide particles is 5 to 100 nm. <4> The inorganic oxide particles according to any one of <1> to <3>, wherein the inorganic oxide particles are selected from the group consisting of silicon oxide particles, zirconium oxide particles, titanium oxide particles and tin oxide particles. <5> The inorganic oxide particle according to any one of <2> to <4>, wherein the B group is an epoxy group and the C group is an amine group. <6> The inorganic oxide particles according to any one of <2> to <5>, wherein the above-mentioned R ⁴ and/or R ⁵ are selected from an alkyl group having 1 to 10 carbon atoms, and an alkyl group having 6 to 40 carbon atoms. A group consisting of aryl and OH groups. <7> The inorganic oxide particles according to any one of <2> to <6>, wherein the inorganic oxide particles are 0.1 to 10 particles/ nm ² surface-modified silicon oxide particles. <8> The inorganic oxide particle according to any one of <1> to <7>, wherein the inorganic oxide particle further has 0.3 to 20 trimethylsilyl groups/nm ² on its surface. <9> A dispersion liquid in which the inorganic oxide particles of any one of <1> to <8> are dispersed in silicone oil. <10> The dispersion of <9>, wherein the silicone oil is dimethyl silicone oil, methyl phenyl silicone oil or methyl hydrogen with a viscosity of 100 centistokes to 5000 centistokes. Silicone oil. <11> A method for producing a surface modifying agent, which is a method for producing a surface modifying agent according to any one of <1> to <8>, and includes: adding to a side chain, a single end, both ends, or a combination thereof The silicone oil containing the functional group (b) and the silane coupling agent containing the functional group (c) are combined in an alcohol solvent, with the functional group (b): functional group (c) being 1:1~1: The molar ratio reaction step of 0.8, the functional group (b) is selected from the group consisting of epoxy group, vinyl group, hydroxyl group or isocyanate group, the functional group (c) is selected from the group consisting of carboxyl group, acid anhydride group, amine group, sulfide group A group of alcohol groups, hydroxyl groups or isocyanate groups. <12> A method for producing a dispersion liquid, which is the method for producing a dispersion liquid of <9> or <10>, and includes: Step (i): Dispersing inorganic oxides in a hydrocarbon solvent with a mixed solvent of hydrocarbons and alcohols The step of mixing the sol and the alcohol solution of the surface modifying agent represented by the general formula (1) at a weight ratio of inorganic oxide: surface modifying agent represented by the general formula (1) = 1:0.1~10, step (ii): in The step of carrying out the reaction at 60~150°C for 0.1~60 hours, step (iii): the step of removing the alcohol solvent to obtain the surface modified inorganic oxide sol dispersed in the hydrocarbon solvent, step (iv): the step of dispersing the surface of the hydrocarbon solvent The step of mixing modified inorganic oxide sol with silicone oil and removing hydrocarbons. [Effects of the invention]

In one aspect of the present invention, silicon oxygen (reactive silicon oxygen) having a reactive functional group at the terminal or side chain of the silicon oxygen molecule is used as a coating agent for inorganic oxide particles (for example, oxidized silicon particles). The silane coupling agent reacts with the above reactive group to synthesize a silicone material with an alkoxysilyl group at the end or side chain of the silicone molecule as a surface modification agent. According to the present invention, since the alkoxysilyl group is hydrolyzed to generate a silanol group, a dehydration reaction occurs with the silanol group on the surface of the silica oxide particles, and a surface modification with a silica skeleton can be strongly formed on the surface of the silica oxide particles. parts. According to one aspect of the present invention, since the surface modification part is located on the surface of the inorganic oxide particles (such as silica oxide particles) and is fixed by siloxane bonding, it will not be detached from the silica oxide particles and can be dispersed in the dispersion medium. Stable and dispersed in silicone oil. According to one aspect of the present invention, since surface-modified inorganic oxide particles (eg, oxidized silicon particles) can be stably dispersed in silicone oil, the silicone oil has excellent long-term stability. According to the present invention, as one aspect, inorganic oxide particles (such as oxidized silicon particles) modified with a specific surface modifier are stably dispersed in silicone oil, which can effectively help improve the refractive index or mechanical properties of the dispersion, and Since they can help improve the transparency of the dispersion, the inorganic oxide particles, surface modifiers and dispersions can be used in various applications, such as formulations of silicone resins or sealants for LEDs. According to the present invention, the above-mentioned inorganic oxide particles are not only silicon oxide particles, but also tin oxide particles, zirconium oxide particles, and titanium oxide particles, which can perform the same function. According to the present invention, as one aspect, a modified polysiloxane having an alkoxysilane present at the end of the polysiloxane is used, whereby a dehydration reaction between the silanol groups is carried out between the silanol groups on the surface of the oxidized silicon particles. , a strong reaction between inorganic substances using Si-O-Si and inorganic substances can be smoothly carried out, and oxidized silicon particles that are fully grafted with polysiloxane on the surface of the oxidized silicon particles can be obtained, and oxidized silicon particles dispersed in silicone oil can be obtained. Silica sol. In addition, inorganic oxide particles such as zirconium oxide particles, titanium oxide particles, and tin oxide particles can be used instead of the above-mentioned silicon oxide particles to form a silicon oxide component on the surface layer, thereby enabling inorganic oxidation by Si-O-Si. The surface of the particles is grafted with polysiloxane.

Preferred embodiments of the present invention will be described below. However, the following embodiments are examples for explaining the present invention, and the present invention is not limited to the following embodiments. In this specification, the numerical range expressed by "~" means the range including the numerical values written before and after "~" as the lower limit and the lower limit.

(Inorganic oxide particles and dispersions in which inorganic oxide particles are dispersed in silicone oil) In one embodiment of the present invention, the inorganic oxidized particles are surface-modified with a surface modifying agent represented by the following general formula (a) or the following general formula (1). In one embodiment of the present invention, a dispersion (sol) containing a dispersion medium containing surface-modified (colloidal) inorganic oxide particles is dispersed in silicone oil, and the surface modifier is represented by the following general formula (a) or A dispersion represented by the following general formula (1).

In the general formula (a), S represents hydrolyzable silane, and K represents silica. In one embodiment of the present invention, the so-called surface-modified (colloidal) inorganic oxide particles refer to hydrolysis of the hydroxyl groups on the surface of the inorganic oxide particles and the alkoxysilyl group of the surface modifying agent of the general formula (a). The generated silanol groups react to form surface modifier molecules of general formula (a) on the surface of the inorganic oxide particles.

In the formula (1), R ¹ represents a methyl group or an ethyl group, R ² represents an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 40 carbon atoms, or a combination thereof, and R ³ includes The linking group of the chemical group obtained by the reaction of B group and C group, B group is epoxy group, vinyl group, hydroxyl group or isocyanate group, C group is carboxyl group, acid anhydride group, amine group, thiol group, hydroxyl group or isocyanate group. Structural unit A is formula (1-1) and formula (1-2), n1 represents an integer from 1 to 3, n2 represents an integer from 0 to 1, n1+n2=3, n3=n4+n5= represents 1~100 n4 is an integer, n4 is 0≦n4≦100, n5 is 1≦n5≦100, ^R4 is a carbon atom that can contain epoxy group, vinyl group, hydroxyl group, isocyanate group, carboxyl group, acid anhydride group, amine group or thiol group An alkyl group with 1 to 10 carbon atoms or an aryl group with 6 to 40 carbon atoms, or an OH group or a hydrogen atom, and the OH group obtained by hydrolysis of the OR ¹ group modifies the silanol group on the surface of the silica particle.

In one embodiment of the present invention, the so-called surface-modified (colloidal) inorganic oxide particles refer to the alkane of the surface modification agent of general formula (a) or general formula (1) through the hydroxyl group on the surface of the inorganic oxide particle and the general formula (1). The silanol group generated by the hydrolysis of the oxysilyl group reacts to form surface modifier molecules of general formula (a) or general formula (1) on the surface of the inorganic oxide particles.

In formula (1-2), R ⁵ represents an alkyl group or carbon number of 1 to 10 carbon atoms that may contain an epoxy group, a vinyl group, a hydroxyl group, an isocyanate group, a carboxyl group, an acid anhydride group, an amino group or a thiol group. 6 to 40 aryl groups, or OH groups or hydrogen atoms, the number of structural units of formula (1-1) in formula (1) is n4, and the number of structural units of formula (1-2) in formula (1) is n5.

In the formula (1), R ¹ represents a methyl group or an ethyl group, which generates a silanol group through hydrolysis and reacts with the silanol group on the surface of the oxidized silicon particles to form a silicon oxygen molecular chain of the formula (1) on the surface of the oxidized silicon particles.

Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, second-butyl, third-butyl, cyclopropyl, etc. Butyl, 1-methylcyclopropyl, 2-methylcyclopropyl, n-pentyl, 1-methyln-butyl, 2-methyln-butyl, 3-methyln-butyl, 1,1 -Dimethyl n-propyl, 1,2-dimethyl n-propyl, 2,2-dimethyl n-propyl, 1-ethyl n-propyl, cyclopentyl, 1-methylcyclobutyl, 2-Methylcyclobutyl, 3-methylcyclobutyl, 1,2-dimethylcyclopropyl, 2,3-dimethylcyclopropyl, 1-ethylcyclopropyl, 2-ethyl Cyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl n-butyl, 1,3-dimethyl n-butyl, 2,2-dimethyl n-butyl, 2,3-dimethyl n-butyl, 3,3-dimethyl n-butyl, 1-ethyl n-butyl, 2-ethyl n-butyl, 1,1,2-trimethyl n-propyl, 1,2,2-trimethyl n-propyl, 1-ethyl n-butyl Base-1-methyl n-propyl, 1-ethyl-2-methyl n-propyl, cyclohexyl, 1-methylcyclopentyl, 2-methylcyclopentyl, 3-methylcyclopentyl, 1-ethylcyclobutyl, 2-ethylcyclobutyl, 3-ethylcyclobutyl, 1,2-dimethylcyclobutyl, 1,3-dimethylcyclobutyl, 2,2- Dimethylcyclobutyl, 2,3-dimethylcyclobutyl, 2,4-dimethylcyclobutyl, 3,3-dimethylcyclobutyl, 1-n-propylcyclopropyl, 2 -n-propylcyclopropyl, 1-isopropylcyclopropyl, 2-isopropylcyclopropyl, 1,2,2-trimethylcyclopropyl, 1,2,3-trimethylcyclopropyl base, 2,2,3-trimethylcyclopropyl, 1-ethyl-2-methylcyclopropyl, 2-ethyl-1-methylcyclopropyl, 2-ethyl-2-methyl Cyclopropyl and 2-ethyl-3-methylcyclopropyl, etc.

Furthermore, examples of the aryl group having 6 to 40 carbon atoms include phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-chlorophenyl, m- -Chlorophenyl, p-chlorophenyl, o-fluorophenyl, p-fluorophenyl, o-methoxyphenyl, p-methoxyphenyl, p-nitrophenyl, p-cyano Phenyl, α-naphthyl, β-naphthyl, o-biphenyl, m-biphenyl, p-biphenyl, 1-anthracenyl, 2-anthracenyl, 9-anthracenyl, 1-phenanthryl , 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl and 9-phenanthrenyl.

The above-mentioned R ² may be used as an arylalkyl group by combining an alkyl group and an aryl group.

The surface modifier of general formula (1) can react the functional group of the reactive silicon oxygen with the functional group of the silane coupling agent to form a linking group R ³ containing a new chemical group formed by the reaction of the two functional groups, which is introduced into the silicon oxygen molecule. Alkoxysilyl. In the formula (1), the number n1 of the alkoxy group of the alkoxysilyl group is 1 to 3. The alkoxysilyl group may include an organic group R ² , and examples thereof include the above-mentioned alkyl group and aryl group. The number n2 of R ² in formula (1) can exemplify an integer from 0 to 1. And n1+n2=3 is an integer.

R ³ in the formula (1) is a linking group including a chemical group obtained by the reaction of a B group and a C group.

The functional groups of both the reactive silicone oxygen and the silane coupling agent respectively include epoxy group, vinyl group, hydroxyl group or isocyanate group for the B group, and carboxyl group, acid anhydride group, amine group, thiol group and hydroxyl group for the C group. or isocyanate group.

The functional group of B group and the functional group of C group form a new chemical group through addition reaction, dehydration reaction or decarbonation reaction, but at this time, water can also participate in the reaction system.

Examples include the addition reaction of epoxy group and carboxyl group, the addition reaction of epoxy group and acid anhydride group, the addition reaction of epoxy group and amine group, the addition reaction of epoxy group and thiol group, the addition reaction of epoxy group Addition reaction with hydroxyl group, addition reaction of vinyl group and thiol group, dehydration reaction of hydroxyl group and hydroxyl group, addition reaction of isocyanate group and carboxyl group, addition reaction of isocyanate group and acid anhydride group, addition reaction of isocyanate group and amine group Addition reaction, addition reaction of isocyanate group and thiol group, addition reaction of isocyanate group and hydroxyl group, cyclization reaction of isocyanate groups with each other. In particular, the addition reaction of an epoxy group and an amine group is preferably used. Examples of R ³ include the following linking groups.

Among the linking groups containing the above chemical groups, T ¹ and T ² are groups included together with the functional groups in the reactive silicon oxygen and silane coupling agents, and can be alkylene groups, aryl groups or a combination thereof, or they can be Contains oxygen or nitrogen atoms. Examples of these alkylene groups and aryl groups include groups corresponding to the above-mentioned alkyl groups and aryl groups and those exemplified above. Also, the ※ mark indicates the bonding part with the silicon atom of the reactive silicon oxygen and silane coupling agent.

In formula (1), structural unit A can represent formula (1-1) and formula (1-2). When the unit structure number n4 in formula (1-1) in formula (1) and the unit structure number n5 in formula (1) are n3, the number n3 of structural unit A in formula (1) is n3=n4+n5=1~ 100, n4 series 0≦n4≦100, n5 series 1≦n5≦100.

R ⁴ and R ⁵ contained in formula (1) respectively represent an alkyl group with 1 to 10 carbon atoms that may contain an epoxy group, a vinyl group, a hydroxyl group, an isocyanate group, a carboxyl group, an acid anhydride group, an amino group or a thiol group. Or an aryl group with 6 to 40 carbon atoms, or an OH group.

In one embodiment of the present invention, the concentration of the inorganic oxide in the dispersion liquid is usually 0.1 to 50 mass%, preferably 10 to 50 mass%, and more preferably 20 to 50 mass%.

In one embodiment of the present invention, the average primary particle size of the inorganic oxide particles is usually 5 to 100 nm, preferably 5 to 30 nm, and more preferably 5 to 20 nm. The average primary particle diameter can be measured using a method of converting particle diameter from specific surface area using a nitrogen adsorption method (BET method) or by observation with a transmission electron microscope. In the present invention, it is expressed by the method of converting the particle size from the specific surface area using the nitrogen adsorption method (BET method).

The inorganic oxide particles can be selected from the group consisting of silicon oxide particles, zirconium oxide particles, titanium oxide particles and tin oxide particles.

The inorganic oxide particles can also be surface modifiers represented by general formula (a) or general formula (1), preferably 0.1 to 10 particles/nm ² , more preferably 0.2 to 4 particles/nm ² , and even more preferably 0.3 ~2pcs/nm ² surface-modified silicon oxide particles.

The inorganic oxide particles can preferably have 0.3~20 particles/nm ² on their surface, more preferably 0.5~10 particles/nm ² , more preferably 1~10 particles/nm ² , and most preferably 0.5~1.0 particles/nm ² Trimethylsilyl. The above-mentioned number of surface modification groups per nm ² is a value calculated based on the surface modification of the surface of the silicon oxide particles through the reaction of the surface modifier added to the silicon oxide particles.

One embodiment of the present invention is a dispersion in which the above-mentioned inorganic oxide particles are dispersed in silicone oil.

Examples of the silicone oil are dimethyl silicone oil, methylphenyl silicone oil or methyl hydrogen silicone oil with a viscosity of 100 centistokes to 5000 centistokes. Examples include KF-96 (100 centistokes), KF-96 (300 centistokes), KF-96 (500 centistokes), and KF-96 (1000 centistokes) manufactured by Shin-Etsu Chemical Industry Co., Ltd. Stoke), KF-96 (5000 centistokes).

(Production method of surface modification agent) The reactive silicone is any type in which the functional group site in the silicone molecule is a single-terminal type, a two-terminal type, a side chain type, or a side chain two-terminal type, but the single-terminal type reactivity can be preferably used. Silica. When selecting a two-terminal type reactive silica, the silane coupling agent can react with one of the selected functional groups by setting the molar ratio of the silane coupling agent to be lower than the molar ratio of the reactive silica. The reactive silica reacts with the silane coupling agent to synthesize the surface modification agent of formula (1). The alkoxy group of the alkoxysilyl group is hydrolyzed, and the generated silanol group reacts with the silanol group on the surface of the oxidized silicon particles, thereby coating the surface of the oxidized silicon particles with a silicon oxygen component.

The functional groups of the silane coupling agent react with the functional groups of the reactive silicon oxygen at a molar ratio of equimolar or less (synthetically speaking, 1:1~1:0.8), and are obtained from one molecule of the reactive silicon oxygen. Surface modifier with one alkoxysilyl group. The alkoxysilyl group in the surface modifier is preferably one in one molecule, which prevents cross-linking of silicon oxide particles and eliminates the causes of aggregation or formation of coarse particles, so it is preferable.

The method of introducing one alkoxysilyl group into one molecule of the surface modification agent can be better produced by reacting single-terminal reactive siloxy with a silane coupling agent. When using single-terminal reactive silicone, R ⁴ and/or R ⁵ in formula (1) and formula (1-2) can be an alkyl group with 1 to 10 carbon atoms, or an alkyl group with 6 to 6 carbon atoms. 40 aryl group or OH group.

The silicone oil containing the functional group (b) in the side chain, single terminal, both terminals or the combination thereof and the silane coupling agent containing the functional group (c) are used in an alcohol solvent to react with the reactive group (b) : A method for producing a surface modifier of formula (1) in which the reactive group (c) is a molar ratio reaction of 1:1 to 1:0.8. The reactive group (b) and the reactive group (c) can be respectively set to A reactive group selected from the group consisting of epoxy group, vinyl group, hydroxyl group or isocyanate group, and a reactive group selected from the group consisting of carboxyl group, acid anhydride group, amine group, thiol group, hydroxyl group or isocyanate group.

(Method for manufacturing dispersion (sol)) In one embodiment of the present invention, a method for generating surface-modified oxidized silica sol by reacting the surface modifier of the general formula (1) with oxidized silica sol and dispersing it in silicone oil may include the following steps ( Methods i)~(iv).

An example of a method for producing a dispersion liquid includes the following steps: Step (i): Disperse the oxidized silica sol and the alcohol solution of the surface modifier of formula (1) in a hydrocarbon solvent in a mixed solvent of hydrocarbon and alcohol, so as to oxidize the silicon: surface modifier of formula (1) = 1: The steps of mixing with a weight ratio of 0.1~10, Step (ii): The step of carrying out the reaction at 60~150°C for 0.1~60 hours, Step (iii): The step of removing the alcohol solvent to obtain the surface-modified oxidized silica sol dispersed in the hydrocarbon solvent, Step (iv): The step of mixing the surface-modified oxidized silica sol dispersed in a hydrocarbon solvent with silicone oil and removing hydrocarbons.

Before removing the hydrocarbon solvent, it was a colorless and transparent dispersion, but after removing the hydrocarbon solvent, it became a transparent, colloidal dispersion.

Examples of the hydrocarbon solvent include normal paraffin, isoparaffin aliphatic hydrocarbons, naphthenic cyclic aliphatic hydrocarbons, and aromatic hydrocarbons. Aromatic hydrocarbons are preferred, and examples thereof include toluene, xylene, ethylbenzene, and the like.

Examples of the alcohol solvent include methanol, ethanol, propanol, isopropyl alcohol, butanol, and the like.

When the surface of the silica particles in the oxidized silica sol is coated with the surface modifier of formula (1), it can be 0.1~10 particles/nm ² or 0.1~5 particles/nm ² , 0.5~5 particles/nm ² or 0.5~1.5 particles/ nm ² ratio coverage.

In the present invention, after being coated with the surface modifier of formula (1), the surface can be further hydrophobicized with trimethylsilyl groups. Examples of the trimethylating agent include trimethylsilyl chloride, hexamethyldisilazane, and hexamethyldisiloxane. The surface of the silica particles in the silica sol can be coated at a ratio of 1 to 20 particles/nm ² or 5 to 15 particles/nm ² .

Examples of the colloidal inorganic oxide particles of the present invention include silicon oxide particles, zirconium oxide particles, and titanium oxide particles with an average primary particle diameter of 5 to 100 nm. Like silicon oxide particles, zirconium oxide particles, titanium oxide particles, and tin oxide particles can also be surface-coated.

In the present invention, the modified polysiloxane containing alkoxysilane at the terminal end of the polysiloxane is used, and the dehydration reaction between the silanol groups on the surface of the oxidized silicon particles is carried out smoothly. The strong reaction between Si-O-Si inorganic substances and inorganic substances can obtain oxidized silicon particles that are fully grafted with polysiloxane on the surface of the oxidized silicon particles, and obtain an oxidized silicon sol dispersed in silicon oxygen oil. In addition, instead of the above-mentioned silicon oxide particles, inorganic oxide particles such as zirconium oxide particles, titanium oxide particles, and tin oxide particles can be used to form a silicon oxide component on the surface layer. Si-O-Si can be added to the inorganic oxide particles. The particle surface is grafted with polysiloxane. Since the zirconium oxide particles or titanium oxide particles form a silicon oxide component on the surface layer, it is preferred to modify the zirconium oxide particles or titanium oxide particles with a substance containing a silicon oxide component, and then graft-modify the polysiloxane.

As the material containing the silicon oxide component, silica oxide colloid particles can be used. The silica oxide colloidal particles used here can also be silica alone. However, in order to adjust the refractive index or improve the adhesion, they can be combined with other metal oxide colloidal particles. For example, the average primary particle size is 5 nm or less. Examples include silicon dioxide-tin oxide composite oxide colloidal particles of 1 to 4 nm.

The oxidized silica sol used as the raw material of the present invention can be used by preparing an aqueous oxidized silica sol and replacing the solvent with an organic solvent oxidized silica sol. The average primary particle size of the silicon oxide particles of the raw material silica sol can be used in the range of 5 to 100 nm. The average primary particle diameter can be measured using a method of converting particle diameter from specific surface area using a nitrogen adsorption method (BET method) or by observation with a transmission electron microscope. In the present invention, it is expressed by the method of converting the particle size from the specific surface area using the nitrogen adsorption method (BET method).

Aqueous oxidized silica sol can be obtained by cation-exchanging a silicate alkali aqueous solution with a solid content concentration of 1 to 10 mass % to obtain a silicic acid solution with a pH of 1 to 6, and heating it at 50°C to 110°C in the presence of an alkali. The above-mentioned cation exchange treatment is performed by contacting with a strongly acidic cation exchange resin. It is carried out by passing the treatment liquid through the ion exchange resin filled in the column.

The obtained aqueous silica oxide sol is contacted with a strong alkaline anion exchange resin to obtain a high-purity alkaline aqueous silica oxide sol. Furthermore, it is further contacted with a strongly acidic cation exchange resin to obtain high-purity acidic aqueous oxidized silica sol. Ultrafiltration for impurity removal or solid content concentration can then be performed.

As the above-mentioned silicate base, sodium silicate, potassium silicate, lithium silicate, etc. can be used, and those sold under the names of No. 1 sodium silicate water glass, No. 2 sodium silicate water glass, and No. 3 sodium silicate water glass can be used. Sodium silicate. In addition, it can be used in silicic acid liquid obtained by hydrolyzing alkoxysilane such as tetraethoxysilane or tetramethoxysilane, and adding sodium hydroxide, potassium hydroxide, lithium hydroxide, and quaternary ammonium hydroxide. Silicic acid base.

In one embodiment of the present invention, the obtained aqueous silica oxide sol can be further subjected to the following steps (I) and (II). Step (I) includes a step (I-i) of maintaining at room temperature ~ 50°C and an acidic condition of pH 1 ~ 4, a step (I-ii) of heating at 100 ~ 200°C, or a combination of these steps (I- iii). Step (II) includes the step (II-i) of sequentially performing cation exchange and anion exchange or the step (II-ii) of sequentially performing cation exchange, anion exchange and cation exchange. In step (I), the step (I-i) of maintaining under acidic conditions of pH 1 to 4 is to use acid to remove sodium ions from the surface of oxidized silicon (a) particles in the aqueous solution of oxidized silicon (a) particles (sol), and Silicon oxide (A) particles that have formed a layer in which sodium ions have been reduced. Adjustment of pH 1~4 can be achieved by adding sulfuric acid, nitric acid, hydrochloric acid, etc. to the aqueous solution of dispersed silicon oxide particles. In the step (I), the step (I-ii) of heating the silicon oxide (a) particle dispersion (sol) at 100~200°C uses an autoclave device to remove sodium ions from the surface of the silicon oxide (a) particles to form Silicon (A) particles that have formed a layer with reduced sodium ions.

Step (I) may be performed in combination with step (I-i) and step (I-ii). For example, step (I-i) can be performed after step (I-ii).

The aqueous sol of silicon oxide (A) is obtained through step (II) after step (I). Step (II) is the step (II-i) of sequentially performing cation exchange and anion exchange or the step (II-ii) of sequentially performing cation exchange, anion exchange and cation exchange, by passing through step (II-ii). A silicon oxide aqueous sol with reduced residual ions is obtained.

The obtained aqueous silica oxide sol can be obtained by replacing water as the dispersion medium with an organic solvent through vacuum distillation, ultrafiltration, etc. Examples of the organic solvent include alcohol solvents such as methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, ethylene glycol, propylene glycol, and butylene glycol; ketones such as acetone and methyl ethyl ketone; and ethyl acetate. Esters such as toluene, xylene, ethylbenzene, etc., hydrocarbons such as dimethylformamide, N-methyl-2-pyrrolidone, etc.

In one embodiment of the present invention, an oxidized silica sol can be obtained by hydrolyzing and polycondensing hydrolyzable alkoxysilane. Examples of alkoxysilane include tetraethoxysilane and tetramethoxysilane. Alkoxysilane is hydrolyzed and polycondensed in a solvent containing water to produce silica oxide sol. Examples of the solvent used include alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, propylene glycol, butylene glycol, ketones such as acetone, methyl ethyl ketone, and ethyl acetate. Esters such as esters, hydrocarbons such as toluene, xylene, ethylbenzene, etc., dimethylformamide, N-methyl-2-pyrrolidone, etc. These solvents can be used as mixed solvents.

The amount of water can be 1 to 10 moles relative to 1 mole of alkoxy group of alkoxysilane.

Examples of the alkali catalyst include alkali metals such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; ammonium; quaternary ammonium hydroxide such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; ethylenediamine, Amines such as diethylenetriamine, diethyltriamine, urea, ethanolamine, etc. (use)

In one embodiment of the present invention, a dispersion liquid containing a dispersion of surface-modified colloidal inorganic oxide particles dispersed in silicone oil can be used as a silicone to improve the refractive index or mechanical properties in conventional applications using silicone oil. Oxygen oil also has high transparency, so the inorganic oxide particles, surface modifiers and dispersions can be used in various applications, such as formulation agents for silicone resins or sealants for LEDs. [Example]

(Synthesis of polymeric silane coupling agent) Feed single-terminal epoxy modified silica (functional group equivalent 4700g/mol, viscosity 60mm ² /s, product name: X-23-173DX) into a 1-liter pear-shaped flask. Shin-Etsu Chemical Industry Co., Ltd.) 128 g, then add 367 g of butanol (Kanto Chemical Industry Co., Ltd.) and stir, then add 3-aminopropyltrimethoxysilane (product name: KBM-903, Shin-Etsu Chemical Industry Co., Ltd. Company-made) 5.0g. Subsequently, the solution was kept at 110° C. for 24 hours with stirring to obtain a 1-butanol solution of the following polymer-type silane coupling agent (polymer concentration: 21.3% by mass). After measuring the epoxy equivalent of the resulting solution, the reaction rate between epoxy groups and amine groups was 80%.

[Example 1] Preparation of toluene-dispersed silicone polymer grafted oxidized silica sol-1 In a 200 ml pear-shaped bottle, 30 g of methanol-dispersed silica oxide sol (product name: MT-ST, average primary particle size 12 nm, silica concentration 30 mass%, manufactured by Nissan Chemical Co., Ltd.) was added, and n-butanol 8.4 was added. g. A part of the dispersion medium of the silica oxide sol was replaced with a toluene solvent using a rotary evaporator to obtain an silica oxide sol dispersed in a solvent with a mixing ratio of toluene and n-butanol of 6:4 (average primary particle size 12 nm, silica oxide concentration 30% by mass) 30g. To this oxidized silica sol, 50 g of an n-butanol solution of the above-mentioned polymeric silane coupling agent was added, and further, 36.7 g of toluene (manufactured by Kanto Chemical Co., Ltd.) was added, and the mixture was maintained at 110° C. for 24 hours with stirring. Subsequently, 5.5 g of hexamethyldisiloxane (product name: KF-96L, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) was added as a trimethylsilyl group, and after heating at 60° C. for 16 hours, hexamethyldisiloxane was added again. Oxane 5.5g, heated at 60°C for 8 hours. The oxidized silica sol thus obtained was replaced with a toluene solvent using a rotary evaporator to obtain a toluene-dispersed silicone polymer-grafted oxidized silica sol (solid content 30.5% by mass, butanol 1.0% by mass, and the remainder being toluene).

(Reference Example 1): Preparation of silica-tin oxide composite oxide colloidal particles as coating and production of modified zirconium oxide sol and modified titanium oxide sol. JIS No. 3 sodium silicate ( _SiO2) containing 29.8 mass %) 77.2g was dissolved in 668.8g of pure water, and then 20.9g of sodium stannate NaSnO ₃・H ₂ O (containing 55.1% by mass in terms of SnO ₂ ) was dissolved. The obtained aqueous solution was passed through a column filled with hydrogen-type cation exchange resin (Amberlite (registered trademark) IR-120B). Next, 7.2 g of diisopropylamine was added to the obtained aqueous dispersion sol. The obtained sol was a water-dispersed sol of alkaline silicon dioxide-tin oxide composite oxide colloidal particles (B1), with a pH of 8.0 and a total metal oxide concentration (SnO ₂ and SiO ₂ ) of 1.7 mass%. The primary particle size observed using a transmission electron microscope is 1~4nm. The water-dispersed sol of the above-mentioned silicon dioxide-tin oxide composite oxide colloidal particles (B1) is mixed with the zirconium oxide sol and the titanium oxide sol respectively, and is manufactured by coating the surfaces of the zirconium oxide particles and titanium oxide particles with the silicon dioxide-tin oxide composite oxide. Composite particles of colloidal particles (B1) replace the aqueous medium with methanol solvent to produce methanol-dispersed zirconia sol (SnO ₂ -SiO ₂ /ZrO ₂ mass ratio = 20:100) and methanol-dispersed titanium oxide sol (SnO ₂ -SiO ₂ /TiO ₂ mass ratio = 30:100). The obtained methanol-dispersed zirconia sol was used in Example 2 described below, and the obtained methanol-dispersed titanium oxide sol was used in Example 3 described below.

[Example 2] Toluene-dispersed silicone polymer-grafted zirconia sol was prepared in a 200 ml pear-shaped bottle. The methanol-dispersed zirconia sol obtained in the above reference example 1 (coated with SnO ₂ with a primary particle size of 1 to 4 nm -Methanol dispersion of zirconia particles with an average primary particle diameter of 17 nm) of SiO ₂ composite particles, 26.5 g of methanol and 35.9 g of n-butanol were added. A part of the dispersion medium of the zirconia sol was replaced with a toluene solvent using a rotary evaporator to obtain a zirconia sol dispersed in a solvent with a mixing ratio of toluene and n-butanol of 2:8 (average primary particle size 17 nm, solid content concentration 20% by mass) 44g. To this zirconia sol, 64 g of a solution containing 39.3 g of toluene was added to 24.7 g of a butanol solution of a polymeric silane coupling agent and maintained at 110° C. for 24 hours while stirring. After the above reaction, 3.9 g of hexamethyldisiloxane as a trimethylsiloxane group was added, and the mixture was heated at 110° C. for 16 hours. Subsequently, 3.9 g of hexamethyldisiloxane was added again, and the mixture was heated at 110° C. for 8 hours. The zirconia sol thus obtained was replaced with a toluene solvent using a rotary evaporator to obtain a toluene-dispersed silicone polymer-grafted zirconia sol (solid content 30.5% by mass, butanol 1.0% by mass, and the remainder being toluene).

[Example 3] Preparation of toluene-dispersed silicone polymer-grafted titanium oxide sol. In a 200 ml pear-shaped bottle, put the methanol-dispersed titanium oxide sol obtained in Reference Example 1 (coated with SnO with a primary particle size of 1 to 4 nm ₂ -SiO ₂ composite particles (methanol dispersion of titanium oxide particles with an average primary particle diameter of 17 nm) 30g, after adding 40.5g of 2-propanol and 40.5g of butanol, 0.9g of glycolic acid was added. A part of the dispersion medium of the titanium oxide sol was replaced with a toluene solvent using a rotary evaporator to obtain a titanium oxide sol dispersed in a solvent with a mixing ratio of toluene and n-butanol of 2:8 (average primary particle size 17 nm, solid content concentration 11.3% by mass) 90g. To this titanium oxide sol, 54.1 g of a solution containing 29.4 g of toluene was added to 24.7 g of a butanol solution of a polymeric silane coupling agent, and the mixture was maintained at 110° C. for 24 hours while stirring. After the above reaction, 3.9 g of hexamethyldisilazane (SZ-31, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) as a trimethylsilyl group was added, and the mixture was heated at 60° C. for 8 hours. The titanium oxide sol thus obtained was replaced with a toluene solvent using a rotary evaporator to obtain a toluene-dispersed silicone polymer-grafted titanium oxide sol (solid content 30.5% by mass, butanol 1.0% by mass, and the remainder being toluene).

[Example 4] Preparation of toluene-dispersed silicone polymer grafted oxidized silica sol-2 In the same manner as Example 1, 30 g of silica oxide sol (average primary particle diameter: 12 nm, silica oxide concentration: 30 mass%) dispersed in a solvent with a mixing ratio of toluene and n-butanol of 6:4 was obtained. To this oxidized silica sol, 25 g of an n-butanol solution of the above-mentioned polymeric silane coupling agent was added, and then 14.2 g of toluene (manufactured by Kanto Chemical Co., Ltd.) was added, and the mixture was maintained at 110° C. for 24 hours with stirring. Subsequently, 5.5 g of hexamethyldisiloxane (product name KF-96L, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) was added as a trimethylsilyl group, heated at 60° C. for 16 hours, and hexamethyldisiloxane was added again. 5.5g of alkane, heated at 60°C for 8 hours. The oxidized silica sol thus obtained was replaced with a toluene solvent using a rotary evaporator to obtain a toluene-dispersed silicone polymer-grafted oxidized silica sol (solid content 30.5% by mass, butanol 1.0% by mass, and the remainder being toluene).

[Example 5] Preparation of toluene-dispersed silicone polymer grafted oxidized silica sol-3 Except that 30 g of methanol-dispersed silica oxide sol (product name: MA-ST-M, average primary particle diameter 22 nm, silica concentration 30% by mass, manufactured by Nissan Chemical Co., Ltd.) was obtained in the same manner as in Example 1, using toluene and 30g of silica oxide sol (average primary particle size 12nm, silica oxide concentration 30% by mass) dispersed in a solvent with a mixing ratio of n-butanol: 6:4. To this oxidized silica sol, 28.8 g of an n-butanol solution of the polymeric silane coupling agent was added, and further 21.1 g of toluene (manufactured by Kanto Chemical Co., Ltd.) was added, and the mixture was maintained at 110° C. for 24 hours with stirring. Subsequently, 3.2 g of hexamethyldisiloxane (product name KF-96L, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) was added as a trimethylsilyl group, and after heating at 60° C. for 16 hours, hexamethyldisiloxane was added again. Oxane 3.2g, heated at 60°C for 8 hours. The oxidized silica sol thus obtained was replaced with a toluene solvent using a rotary evaporator to obtain a toluene-dispersed silicone polymer-grafted oxidized silica sol (solid content 30.5% by mass, butanol 1.0% by mass, and the remainder being toluene).

(Reference Example 2): Production of modified tin oxide sol coated with silicon dioxide-tin oxide composite oxide colloidal particles Dissolve 37.5 kg of oxalic acid ((COOH) ₂・2H ₂ O) in 383 kg of pure water, and Take it into a 500L container, heat it to 70°C with stirring, and add 150kg of 35 mass% hydrogen peroxide water and 75kg of metal tin (manufactured by Shanshi Metal Co., Ltd., trade name: AT-SNNO200N). The addition of hydrogen peroxide water and metallic tin is carried out interactively. First, add 10 kg of 35 mass% hydrogen peroxide water, and then add 5 kg of metallic tin. Wait for the reaction to end (this period is 5 to 10 minutes) and repeat the operation. After adding the entire amount of hydrogen peroxide water and metallic tin, 10 kg of 35 mass% hydrogen peroxide water was added. The time required for adding hydrogen peroxide water and metallic tin is 2.5 hours. After the addition is completed, the reaction is further heated at 95°C for 1 hour to complete the reaction. The molar ratio of hydrogen peroxide water to metallic tin is 2.61 expressed as H ₂ O ₂ /Sn. The obtained tin oxide aqueous sol has very good transparency. The yield of the tin oxide aqueous sol is 630kg, the specific gravity is 1.154, the pH is 1.51, and it is 14.7% by mass in terms of SnO ₂ . The obtained sol was observed under a transmission electron microscope and was found to be spherical with a primary particle size of 10 to 15 nm and fully dispersed colloidal particles. The sol showed a slight increase in viscosity as it was left to stand, but no gelation was seen after being left at room temperature for 6 months, indicating that it was stable. 231 kg of 35 mass % hydrogen peroxide water and 52 kg of pure water were added to 629 kg of the obtained sol, and the molar ratio was adjusted to 10 mass % in terms of SnO ₂ relative to the oxalic acid H ₂ O ₂ /(COOH) ₂ at the time of feeding. After reaching 8.0, it was heated at 95°C for 5 hours of aging. Through this operation, the oxalic acid contained in the product is decomposed into carbon dioxide gas and water due to the reaction with hydrogen peroxide. After the tin oxide slurry obtained by this operation is cooled to about 40°C, the liquid is passed into a catalyst tower filled with about 1.5L of platinum-based catalyst (trade name: N-220 manufactured by Sud Chemie Catalyst Co., Ltd.) and circulated , carry out decomposition treatment of excess hydrogen peroxide. The liquid flow rate is about 30L/min and the circulation is carried out for 5 hours. The liquid was further passed through a column filled with an anion exchange resin (Amberlite (registered trademark) IRA-410: manufactured by Organo Corporation) to obtain 1545 kg of acidic tin oxide aqueous sol. The obtained acidic tin oxide aqueous sol-based SnO ₂ concentration was 11.4% by mass, pH was 3.97, and conductivity was 55 μS/cm. The water-dispersed sol of the above-mentioned silicon dioxide-tin oxide composite oxide colloidal particles (B1) is mixed with the tin oxide sol to produce composite particles in which the surface of the tin oxide particles is coated with the silicon dioxide-tin oxide composite oxide colloidal particles (B1). The aqueous medium was replaced with methanol solvent to produce a methanol-dispersed tin oxide sol (SnO ₂ -SiO ₂ /SnO ₂ mass ratio = 15:100). The obtained methanol-dispersed tin oxide sol was used in Example 6 described below.

[Example 6] Preparation of toluene-dispersed silicone polymer-grafted tin oxide sol. In a 200 ml pear-shaped bottle, the methanol-dispersed tin oxide sol obtained in Reference Example 2 (manufactured by Nissan Chemical Co., Ltd., coated with SnO ₂ - 30g of methanol dispersion of tin oxide particles with an average primary particle size of 21 nm in the SiO ₂ composite particles, and 28.4g of n-butanol were added. A part of the dispersion medium of the tin oxide sol was replaced with a toluene solvent using a rotary evaporator to obtain a tin oxide sol dispersed in a solvent with a mixing ratio of toluene and n-butanol of 2:8 (average primary particle size 17 nm, solid content concentration 20% by mass) 44g. To this tin oxide sol, 24.7 g of a butanol solution of a polymeric silane coupling agent was added, and 63.7 g of a solution containing 39 g of toluene was mixed, and the mixture was kept at 110° C. for 24 hours while stirring. After the above reaction, 2.5 g of hexamethyldisilazane as a trimethylsilyl group was added, and the mixture was heated at 110° C. for 16 hours. Subsequently, 2.5 g of hexamethyldisilazane was added again, and the mixture was heated at 110° C. for 8 hours. The tin sol thus obtained was replaced with a toluene solvent using a rotary evaporator to obtain a toluene-dispersed silicone polymer-grafted tin oxide sol (solid content 30.5% by mass, butanol 1.0% by mass, and the remainder being toluene).

[Comparative Example 1] Preparation of toluene-dispersed phenyltrimethoxysilane-coated oxidized silica sol In Example 1, a toluene-dispersed phenyltrimethoxysilane-coated oxidized silica sol was obtained in the same manner as in Example 1, except that 50 g of n-butanol solution of the polymeric silane coupling agent was replaced with 1.5 g of phenyltrimethoxysilane. (Solid content: 30.5 mass%, butanol 1.0 mass%, and the remainder is toluene).

[Comparative Example 2] Preparation of methyl ethyl ketone-dispersed phenyltrimethoxysilane-coated zirconia sol In Example 2, methyl ethyl ketone was obtained in the same manner as in Example 2, except that 50 g of n-butanol solution of the polymeric silane coupling agent was replaced with 1.0 g of phenyltrimethoxysilane, and methyl ethyl ketone was used instead of toluene. Ketone-dispersed phenyltrimethoxysilane-coated zirconia sol (solid content 30.5 mass%, butanol 1.0 mass%, and the remainder is methyl ethyl ketone).

[Comparative Example 3] Toluene-dispersed single-terminal epoxy-modified silica-coated oxidized silica sol was produced during the synthesis of polymeric silane coupling agent. Single-terminal epoxy-modified silica (functional group equivalent 4700g/mol, viscosity 60mm ² /s, product name: 4700g/mol, viscosity ^60mm2 /s, product name: Oxidized silica sol (solid content 30.5% by mass, butanol 1.0% by mass, and the remainder is toluene).

(Dispersion of the above sol into silicone oil) In a 20 ml glass sample bottle, take 2 g of dimethyl silicone oil (trade name KF-96: viscosity 100 centistokes, average molecular weight 5500, KF-96: viscosity 300 centistokes, average molecular weight 10000, KF-96: viscosity 500 centistokes, average molecular weight 18000, KF-96: viscosity 1000 centistokes, average molecular weight 25000, both manufactured by Shin-Etsu Chemical Co., Ltd.), add 2g of toluene to each to prepare silicone solution.

Subsequently, 2 g of the toluene-dispersed silica grafted oxidized silica sol obtained in Example 1 was added to each, and the mixture was heated and stirred at 220° C. for 1 hour on a hot plate to volatilize and remove toluene, and the appearance of the dispersion after removal of the toluene solvent was evaluated.

The toluene-dispersed silicone-grafted zirconia sol obtained in Example 2, the toluene-dispersed silicone polymer-grafted titanium oxide sol obtained in Example 3, and the toluene-dispersed phenyltrimethoxysilane-coated silica obtained in Comparative Example 1 were evaluated in the same manner. sol, the methyl ethyl ketone-dispersed phenyltrimethoxysilane-coated zirconia sol obtained in Comparative Example 2, and the toluene-dispersed single-terminal epoxy-modified silica-coated zirconia sol obtained in Comparative Example 3.

[Table 1] Silicone oil KF-96 100CS KF-96 300CS KF-96 500CS KF-96 1000CS Example 1 Colorless and transparent Colorless and transparent Colorless and transparent Colorless and transparent Example 2 Transparent gel color Transparent gel color Transparent gel color --- Example 3 Transparent gel color Transparent gel color --- --- Example 4 Colorless and transparent Colorless and transparent Colorless and transparent Colorless and transparent Example 5 Colorless and transparent Transparent gel color --- --- Example 6 Transparent gel color --- --- --- Comparative example 1 White turbidity White turbidity White turbidity White turbidity Comparative example 2 White turbidity White turbidity White turbidity White turbidity Comparative example 3 White turbidity White turbidity White turbidity White turbidity (---) in Table 1 indicates that measurement was not performed. In Table 1, colorless and transparent means a range with a transmittance of 95%, transparent colloidal color means a range with a transmittance of 94 to 70%, and white turbidity means a range with a transmittance of 1% or less. In addition, the transmittance was measured using a quartz unit with an optical path of 2 mm. The irradiation light was 650 nm light in Examples 1 to 3 and Comparative Examples 1 to 3, and 520 nm light in Examples 4 to 6. [Industrial availability]

A dispersion containing the dispersion of the surface-modified colloidal inorganic oxide particles of the present invention dispersed in silicone oil can be used as a silicone oil to improve the refractive index or mechanical properties of conventional silicone oils, and, Due to their high transparency, the inorganic oxide particles, surface modification agents and dispersions can be used in various applications such as formulation agents for silicone resins or sealants for LEDs.

Claims (10)

An inorganic oxide particle, which is surface-modified with a surface modifying agent represented by the following general formula (1), and the inorganic oxide particle is selected from the group consisting of silicon oxide particles, zirconium oxide particles, titanium oxide particles, and tin oxide particles The group formed,

[In formula (1), R ¹ represents a methyl group or an ethyl group, R ² represents an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 40 carbon atoms, or a combination thereof, and R ³ includes The linking group of chemical groups obtained by the reaction of B group and C group. B group is epoxy group, vinyl group, hydroxyl group or isocyanate group. C group is carboxyl group, acid anhydride group, amine group, thiol group, hydroxyl group or isocyanate group. , R ⁴ is an alkyl group with 1 to 10 carbon atoms or an aryl group with 6 to 40 carbon atoms, which may contain an epoxy group, vinyl group, hydroxyl group, isocyanate group, carboxyl group, acid anhydride group, amino group or thiol group. Or OH group, and the silanol group on the surface of the silica particle is modified by the OH group obtained by the hydrolysis of the OR ¹ group. The unit structure A includes the unit structure of the following general formula (1-1) and the following general formula ( 1-2), and the number of unit structures of general formula (1-1) and the number of unit structures of general formula (1-2) included in unit structure A are n4 and n5 respectively,

(In formula (1-2), R ⁵ represents an alkyl group or carbon atom with 1 to 10 carbon atoms that may contain an epoxy group, vinyl group, hydroxyl group, isocyanate group, carboxyl group, acid anhydride group, amino group or thiol group. Aryl group with number 6~40, or OH group or hydrogen atom), n1 is an integer between 1~3, n2 is an integer between 0~1, n1+n2=3, n3=n4+n5, n3 is an integer between 1~100 Integer, 0≦n4≦100, 1≦n5≦100]. Such as the inorganic oxide particles of claim 1, wherein the average primary particle diameter of the inorganic oxide particles is 5~100nm. Such as the inorganic oxide particles of claim 1, wherein the B group is an epoxy group and the C group is an amine group. Such as the inorganic oxide particles of claim 1, wherein the above-mentioned R ⁴ and/or R ⁵ are selected from the group consisting of an alkyl group with 1 to 10 carbon atoms, an aryl group with 6 to 40 carbon atoms, and an OH group. Such as the inorganic oxide particles of claim 1 or 2, wherein the inorganic oxide particles are silicon oxide particles surface-modified by a surface modifier represented by the general formula (1) at a rate of 0.1 to 10 particles/nm ² . Such as the inorganic oxide particles of claim 1 or 2, wherein the inorganic oxide particles further have 0.3 to 20 trimethylsilyl groups/nm ² on their surfaces. A dispersion liquid in which the inorganic oxide particles according to any one of claims 1 to 6 are dispersed in silicone oil. For example, the dispersion of claim 7, wherein the silicone oil is dimethyl silicone oil, methylphenyl silicone oil or methyl hydrogen silicone oil with a viscosity of 100 centistokes to 5000 centistokes. . A method for producing a surface modifying agent, which is the method for producing a surface modifying agent according to any one of claims 1 to 6, and includes: a site formed of a side chain, a single end, both ends, or a combination thereof Silicone oil containing functional group (b) and silane coupling agent containing functional group (c) are placed in an alcohol solvent, with the molar ratio of functional group (b):functional group (c) being 1:1~1:0.8 In the reaction step, the functional group (b) is selected from the group consisting of epoxy group, vinyl group, hydroxyl group or isocyanate group, and the functional group (c) is selected from the group consisting of carboxyl group, acid anhydride group, amine group, thiol group, hydroxyl group or A group of isocyanate groups. A method for producing a dispersion liquid, which is the method for producing a dispersion liquid according to claim 7 or 8, and includes: step (i): in a hydrocarbon solvent, a mixed solvent of hydrocarbon and alcohol is used to disperse the inorganic oxide sol and the general formula (1) The step of mixing the alcohol solution of the surface modifying agent represented by the inorganic oxide: the surface modifying agent represented by the general formula (1) = 1:0.1~10 in a weight ratio, step (ii): at 60~150°C The steps of carrying out the reaction for 0.1 to 60 hours, step (iii): removing the alcohol solvent to obtain the surface-modified inorganic oxide sol dispersed in the hydrocarbon solvent, step (iv): oxidizing the surface-modified inorganic oxide dispersed in the hydrocarbon solvent soluble matter The step of mixing glue and silicone oil and removing hydrocarbons.